diff --git a/chapter3/bases.c b/chapter3/bases.c
new file mode 100644
index 0000000..da4f1a8
--- /dev/null
+++ b/chapter3/bases.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main(){
+	int x = 100;
+	printf("dec = %d;octal = %o, hex = %x\n", x, x, x);
+	printf("dec = %d;octal = %#o, hex = %#x\n", x, x, x);
+
+	return 0;
+}